As the usage of computers becomes more widespread and the technology to produce them advances, factors that affect consumer choice are no longer limited to speed and storage space; rather, factors such as the ease of portability, durability, and aesthetic design of computers become an important factor in consumer choice of computers. The latest trend in PC development has been to reduce the size of computers. The success of this trend is evident by the new machines that are available on the market, such as Lenovo's Ultra Small Form Factor machines, and the Apple miniMAC systems.
The success of creating smaller computers has been somewhat marred by the challenge of cooling the system. These smaller computers, equipped with the latest processors (for example Intel's latest desktop processor Intel® Pentium® D processor), create significant complexity for system designers because the CPU has more wattage and expects more cooling from the system. When the Intel® Pentium® D processor was placed in systems designed for previous generation processors, the fan was forced to run at full speed to cool the system, resulting in noise-related issues.
The fans that are well-known in the art are no longer simply binary fans that either run On or Off. Rather, the fans that are well-known in the art are connected to a temperature sensor. As the system runs a high number of programs or computation-intensive programs, the system gets hotter and causes the fan to spin faster. The speed of the fans is directly proportional to the amount of air that is flowed through to cool the system. As the fans spin faster, the noise from the fans increases.
Fan noise is sometimes tolerated by a class of “power users” that expect high power and realize that workstations are noisier when running intensive applications. However, this noise is not tolerated during less intensive applications. For example, users will not accept a small form factor desktop with a screen saver running that results in fan noise that sounds like a turbo propeller.
During in-house research, Lenovo has found that certain screen savers chosen by users are as CPU intensive as complex calculations such as intensive applications like N-factorial. In response, Lenovo has introduced a “quiet mode” which limits the CPU performance to half speed, and consequently reduces the fan noise to a specified level. However, the drawback to this is a significant loss of performance. This causes a conundrum because customers do not want to lose performance for critical applications, but also do not want to deal with the noise for noncritical applications. Intel has also invested in power savings technology for mobile processors, which are significantly more expensive and offer lower performance than existing desktop processors. These prior art technologies often only detail thermal fan control based solely on temperature measurements.
Thus, there exists a need in the art for a method or system which is able to provide some thermal fan control of the computer based on user activity and application type. Such a method would ensure a more quiet and efficient fan without affecting the performance of the system for critical applications.